Starting an animation on the birth of a particle or using animation nodes?
Solution

This can easily be achieved by subtracting the birth time of each particle form the time input of the required animation.

Lets assume that your animation is a simple 180 turn around the z axis, then I can just generate the rotations as follows:



What happens is when you subtract the birth time of the particle, the time of the animation becomes zero at the time of its birth and it linearly and continuously increases. Other complex and advances animations and scenarios can be achieved on the bases of the previously described concept.

Appendix

In case you don't know how to make a group like particle system, here is a simple a node tree that does exactly that: